(19)
(11) EP 0 862 198 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
11.11.1998 Bulletin 1998/46

(43) Date of publication A2:
02.09.1998 Bulletin 1998/36

(21) Application number: 98301106.5

(22) Date of filing: 16.02.1998
(51) International Patent Classification (IPC)6: H01J 25/58, H01J 23/02, H01J 23/075, H01F 7/02, H01F 3/10
(84) Designated Contracting States:
AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE
Designated Extension States:
AL LT LV MK RO SI

(30) Priority: 28.02.1997 JP 46532/97

(71) Applicant: SHARP KABUSHIKI KAISHA
Osaka-shi, Osaka-fu 545 (JP)

(72) Inventors:
  • Ide, Tetsuya
    Yokohama-shi, Kanagawa (JP)
  • Uda, Keiichiro
    Kashiwa-shi, Chiba (JP)
  • Yano, Seiki
    Yamatokoriyama-shi, Nara (JP)

(74) Representative: Brown, Kenneth Richard et al
R.G.C. Jenkins & Co. 26 Caxton Street
London SW1H 0RJ
London SW1H 0RJ (GB)

   


(54) A plate-type magnetron


(57) A plate-type magnetron has a cathode (13) for emitting electrons and plate shaped anode (11) having a multiple number of vanes (12) arranged at regular intervals thereon, forming an interaction space (18). Provided on both sides of the interaction space are a pair of pole pieces (14) which are formed of bellows, and hence flexible in their length, and an adjustable magnetic portion (16). A yoke (15) is provided, which is used to alter the distance between the magnets, so that the frequency of the microwaves can be changed. A pair of electrodes (20) arranged facing each other perpendicularly to the magnetic field on both sides of the interaction space (18) is also provided, and the applied voltage to the electrodes is changed to thereby change the output power of microwaves.






Search report